Three dimensions of the problems associated with a dramatic change in the definition, processing, and treatment of New York State felony defendants who are incompetent to stand trial are being studied: (1) the question of dangerousness - how is this concept being defined by the courts and psychiatrists who must formally make this determination for the first time under a September, 1971 statute? What criteria are being used to predict dangerousness? What is the validity of these predictions?; (2) the level and type of organizational adaptation necessitated by a Department of Mental Hygiene becoming responsible for the care and detainment of individuals formerly under the custody of a Department of Corrections; and (3) the histories and institutional careers of people labeled incompetent defendants.